WO1993002271A1 - Extensible ladder - Google Patents

Extensible ladder Download PDF

Info

Publication number
WO1993002271A1
WO1993002271A1 PCT/GB1992/001319 GB9201319W WO9302271A1 WO 1993002271 A1 WO1993002271 A1 WO 1993002271A1 GB 9201319 W GB9201319 W GB 9201319W WO 9302271 A1 WO9302271 A1 WO 9302271A1
Authority
WO
WIPO (PCT)
Prior art keywords
section
uprights
ladder
rung
extensible ladder
Prior art date
Application number
PCT/GB1992/001319
Other languages
French (fr)
Inventor
Ronald Barry Thomas Jones
Original Assignee
Foxdale Limited
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Foxdale Limited filed Critical Foxdale Limited
Publication of WO1993002271A1 publication Critical patent/WO1993002271A1/en

Links

Classifications

    • E—FIXED CONSTRUCTIONS
    • E06—DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
    • E06C—LADDERS
    • E06C1/00—Ladders in general
    • E06C1/02—Ladders in general with rigid longitudinal member or members
    • E06C1/04—Ladders for resting against objects, e.g. walls poles, trees
    • E06C1/08—Ladders for resting against objects, e.g. walls poles, trees multi-part
    • E06C1/12—Ladders for resting against objects, e.g. walls poles, trees multi-part extensible, e.g. telescopic
    • E06C1/125—Ladders for resting against objects, e.g. walls poles, trees multi-part extensible, e.g. telescopic with tubular longitudinal members nested within each other

Definitions

  • This invention relates to an extensible ladder which when collapsed occupies minimal space, yet which can be extended quickly when required for use.
  • an extensible ladder which occupies minimal space when collapsed, yet which can be extended quickly and easily when required for use and which is strong and rigid when extended.
  • an extensible ladder which comprises a plurality of sections, each having a pair of uprights connected by a rung, with the uprights of each section being slidably engaged with " the corresponding uprights of an adjacent section, the rung of each section being spaced frorr. the end from which the adjacent section slides and the uprights of each section being formed with slots to receive the rung of the adjacent section as the latter is collapsed.
  • each section are tubular and preferably rectangular in cross-section.
  • each rung has a pair of spring-loaded bolts which engage into apertures formed in the uprights of the adjacent section when the latter is extended.
  • the bolts are non-circular (e.g. rectangular) in cross-section and the apertures into which they engage are correspondingly shaped.
  • the rung of one section slides into the slots of the other to abut the rung of that other section.
  • the rungs of the successive sections of the ladder are progressively closer to the end into which the next section slides: when the ladder is fully collapsed, the rungs of all sections slide into the slots of one end section (preferably the bottom section) and the uprights of all sections also slide fully into ihe uprights of that end section.
  • an extensible ladder which comprises a plurality of sections, each having a pair of uprights connected by a rung, with the uprights of each section being slidably engaged with the corresponding uprights of an adjacent section and each rung having a pair of spring-loaded bolts which engage into apertures formed in the uprights of the adjacent section when the latter is extended.
  • the ladder may be made from aluminium or plastics.
  • FIGURE 1 is a view of the bottom portion of an extensible ladder in accordance with this invention, when the ladder is extended;
  • FIGURE 2 is a view of the upper section of the ladder
  • FIGURE 3 is a view of the ladder when collapsed
  • FIGURE 4 is an underside view of a rung of the ladder
  • FIGURE 5 is a view to show the manner in which each rung is fixed to its uprights.
  • an extensible ladder which is formed from aluminium components and is light in weight: the ladder may be used as an escape ladder or for other purposes, the ladder having the advantages that it occupies little space when collapsed yet it can be extended to a rigid structure very quickly and easily.
  • the ladder comprises a plurality of sections which are telescopically coupled with one another.
  • Each section comprises a pair of tubular uprights 10, 11 which are rectangular in cross-section, and a rung 12 interconnecting them.
  • the uprights of each section of the ladder engage, as a close but sliding fit, into the uprights of the next section below.
  • the rung of each section is spaced from the top of the uprights of that section, and slots e.g. 13 are formed in the inner wall of each upright from its rung 12 to its top.
  • the uprights of the different sections are all the same height as each other, but are progressively smaller in cross-section towards the top section, and the distance of rhe rung from the top of its uprights, in the successive ladder sections, is progressively less towards the top section.
  • each bolt When the ladder is extended, spring-loaded rectangular cross-section bolts e.g. 14 within each rung engage within rectangular apertures e.g. 15 formed in the inner walls of the uprights of the next-up ladder section.
  • the top ladder section is pulled out until the bolts of the next-down section spring into its locking apertures, then that next section is pulled out, and so on.
  • the bolts of the bottom ladder section In order to collapse the ladder, the bolts of the bottom ladder section must be retracted so that the next section can slide into the uprights of the bottom section, then the bolts of that next section must be retracted, and so on.
  • each bolt In order to retract the bolts of each ladder section, each bolt has a projection 16 extending through an edge of the body 17 in which the bolt slides.
  • each rung comprises a flat strip of aluminium having a channel-section strip 17 of aluminium welded, by its flanges 18, to the underside of the flat strip.
  • the locking bolts 14 slide within the channel and springs 19 act between the bolts 14 and a block 20 fixed in the channel half-way along its length.
  • Figure 5 shows the manner in which the end of each rung may be fixed to its upright.
  • a tab 21 is bent out from the inner wall of the upright 12 at the bottom of the slot 13, and two tabs 22 are also bent out from the same inner wall, but from the top of two shoulders part-way up the slot 13.
  • the rung seats on these tabs, with tabs 22 lying under the flanges of the channel-section strip and tab 21 lying under the bottom of the latter strip.
  • the tabs 21, 22 are spot- ⁇ welded to the rung: the bolt 14 projects through the slot 13 at the bottor. of the latter, between the shoulders carrying the tabs 22.
  • the sections When the ladder is collapsed, as shown in Figure 3, the sections may be locked together by a bar 30, having slots 31 at its opposite ends to engage over projections 32, 33 from the top edge of the outer wall of the bottom ladder section.
  • Projection 33 is bent outwards so that one end of the bar 30 must be positioned at an angle in order to engage over projection 33, after which the bar 30 is pivoted around the projection in order for its other end to engage over projection 32: the latter projection is formed with a hole 34 for insertion of a peg to lock the bar 30 in place.
  • the bar 30 has a carrying, handle 35 fixed to its upper side half-way along its length, to facilitate carrying the ladder when collapsed. It will be noted that the ladder is particularly compact when collapsed. However it is easy and quick to extend, in the manner described above.
  • the ladder When extended, the ladder forms a very rigid structure: this is helped because the uprights of each section are a close sliding fit in the uprights of the section below, and also because a substantial length of each upright is still disposed within the corresponding upright of the ladder section below.
  • the bolts 14 are a close sliding fit within their rungs and also within the apertures 15 in the inner walls of the adjacent ladder section: because the bolts are non-circular in cross- section ana the spaces in which they slide are corresponding in shape, a further means is provided to restrain flexing movement of one ladder section relative to the next.
  • brackets For use as an escape ladder, brackets may be fixed to the outside wall of a house etc. just below the window: then the ladder can be hung upside-down from these brackets, by means of a cross-bar 36 extending between the uprights of the bottom ladder section. Once hung upside-down in this manner and released, the successive ladder sections extend under gravity and automatically lock into position relative to each other as the apertures 15 of the successive uprights align with the bolts 14 of the adjacent section.
  • the ladder may be made from plastics (instead of aluminium): in this case, the springs 19 may be replaced by resilient (e.g. rubber) elements.

Landscapes

  • Ladders (AREA)

Abstract

An extensible ladder comprises a plurality of sections, each having a pair of uprights (10, 11) connected by a rung (12), with the uprights of each section slidably engaged with the corresponding uprights of an adjacent section. The rung of each section is spaced from the end from which the adjacent section slides and the uprights (10, 11) of each section are formed with slots (13) to receive the rung (12) of the adjacent section as the ladder is collapsed. Each rung (12) has a pair of spring-loaded bolts which engage into apertures formed in the uprights of the adjacent section when the latter is extended.

Description

x ens e a e
This invention relates to an extensible ladder which when collapsed occupies minimal space, yet which can be extended quickly when required for use.
Various types of extensible ladder have been proposed hitherto, for example for use as a means of escape from a building in the event of a fire or other emergency. However these known ladders have suffered various drawbacks, being either difficult and time-consuming to extend when needed, or being insufficiently rigid when extended, or occupying substantial space when collapsed.
I have now devised an extensible ladder which occupies minimal space when collapsed, yet which can be extended quickly and easily when required for use and which is strong and rigid when extended. In accordance with this invention there is provided an extensible ladder which comprises a plurality of sections, each having a pair of uprights connected by a rung, with the uprights of each section being slidably engaged with" the corresponding uprights of an adjacent section, the rung of each section being spaced frorr. the end from which the adjacent section slides and the uprights of each section being formed with slots to receive the rung of the adjacent section as the latter is collapsed.
Preferably the uprights of each section are tubular and preferably rectangular in cross-section. Preferably each rung has a pair of spring-loaded bolts which engage into apertures formed in the uprights of the adjacent section when the latter is extended. Preferably the bolts are non-circular (e.g. rectangular) in cross-section and the apertures into which they engage are correspondingly shaped.
When the ladder is collapsed, the rung of one section slides into the slots of the other to abut the rung of that other section. The rungs of the successive sections of the ladder are progressively closer to the end into which the next section slides: when the ladder is fully collapsed, the rungs of all sections slide into the slots of one end section (preferably the bottom section) and the uprights of all sections also slide fully into ihe uprights of that end section. Also in accordance with this invention therefore, there is provided an extensible ladder which comprises a plurality of sections, each having a pair of uprights connected by a rung, with the uprights of each section being slidably engaged with the corresponding uprights of an adjacent section and each rung having a pair of spring-loaded bolts which engage into apertures formed in the uprights of the adjacent section when the latter is extended.
The ladder may be made from aluminium or plastics. An embodiment of this invention will now be described by way of example only and with reference to the accompanying drawings, in which:
FIGURE 1 is a view of the bottom portion of an extensible ladder in accordance with this invention, when the ladder is extended;
FIGURE 2 is a view of the upper section of the ladder; FIGURE 3 is a view of the ladder when collapsed; FIGURE 4 is an underside view of a rung of the ladder; and FIGURE 5 is a view to show the manner in which each rung is fixed to its uprights.
Referring to the drawings, there is shown an extensible ladder which is formed from aluminium components and is light in weight: the ladder may be used as an escape ladder or for other purposes, the ladder having the advantages that it occupies little space when collapsed yet it can be extended to a rigid structure very quickly and easily.
The ladder comprises a plurality of sections which are telescopically coupled with one another. Each section comprises a pair of tubular uprights 10, 11 which are rectangular in cross-section, and a rung 12 interconnecting them. The uprights of each section of the ladder engage, as a close but sliding fit, into the uprights of the next section below. The rung of each section is spaced from the top of the uprights of that section, and slots e.g. 13 are formed in the inner wall of each upright from its rung 12 to its top. The uprights of the different sections are all the same height as each other, but are progressively smaller in cross-section towards the top section, and the distance of rhe rung from the top of its uprights, in the successive ladder sections, is progressively less towards the top section. When the ladder is extended, the rungs are all an equal distance apart from each other. It will be noted that as the ladder collapses and the uprights of each section slide into the uprights of the section below, the rung of each ladder section slides down the slots 13 of the section or sections below. In the collapsed condition as shown in Figure 3, all of the rungs are disposed flat one-upon-another and all of the uprights lie within one- another and within the uprights of the bottom ladder section.
When the ladder is extended, spring-loaded rectangular cross-section bolts e.g. 14 within each rung engage within rectangular apertures e.g. 15 formed in the inner walls of the uprights of the next-up ladder section. Thus in order to extend the ladder, the top ladder section is pulled out until the bolts of the next-down section spring into its locking apertures, then that next section is pulled out, and so on. In order to collapse the ladder, the bolts of the bottom ladder section must be retracted so that the next section can slide into the uprights of the bottom section, then the bolts of that next section must be retracted, and so on. In order to retract the bolts of each ladder section, each bolt has a projection 16 extending through an edge of the body 17 in which the bolt slides.
As shown in Figure 4, each rung comprises a flat strip of aluminium having a channel-section strip 17 of aluminium welded, by its flanges 18, to the underside of the flat strip. The locking bolts 14 slide within the channel and springs 19 act between the bolts 14 and a block 20 fixed in the channel half-way along its length.
Figure 5 shows the manner in which the end of each rung may be fixed to its upright. A tab 21 is bent out from the inner wall of the upright 12 at the bottom of the slot 13, and two tabs 22 are also bent out from the same inner wall, but from the top of two shoulders part-way up the slot 13. The rung seats on these tabs, with tabs 22 lying under the flanges of the channel-section strip and tab 21 lying under the bottom of the latter strip. The tabs 21, 22 are spot-^welded to the rung: the bolt 14 projects through the slot 13 at the bottor. of the latter, between the shoulders carrying the tabs 22.
When the ladder is collapsed, as shown in Figure 3, the sections may be locked together by a bar 30, having slots 31 at its opposite ends to engage over projections 32, 33 from the top edge of the outer wall of the bottom ladder section. Projection 33 is bent outwards so that one end of the bar 30 must be positioned at an angle in order to engage over projection 33, after which the bar 30 is pivoted around the projection in order for its other end to engage over projection 32: the latter projection is formed with a hole 34 for insertion of a peg to lock the bar 30 in place. The bar 30 has a carrying, handle 35 fixed to its upper side half-way along its length, to facilitate carrying the ladder when collapsed. It will be noted that the ladder is particularly compact when collapsed. However it is easy and quick to extend, in the manner described above. When extended, the ladder forms a very rigid structure: this is helped because the uprights of each section are a close sliding fit in the uprights of the section below, and also because a substantial length of each upright is still disposed within the corresponding upright of the ladder section below. Further, the bolts 14 are a close sliding fit within their rungs and also within the apertures 15 in the inner walls of the adjacent ladder section: because the bolts are non-circular in cross- section ana the spaces in which they slide are corresponding in shape, a further means is provided to restrain flexing movement of one ladder section relative to the next.
For use as an escape ladder, brackets may be fixed to the outside wall of a house etc. just below the window: then the ladder can be hung upside-down from these brackets, by means of a cross-bar 36 extending between the uprights of the bottom ladder section. Once hung upside-down in this manner and released, the successive ladder sections extend under gravity and automatically lock into position relative to each other as the apertures 15 of the successive uprights align with the bolts 14 of the adjacent section.
The ladder may be made from plastics (instead of aluminium): in this case, the springs 19 may be replaced by resilient (e.g. rubber) elements.

Claims

Claims
1) An extensible ladder which comprises a plurality of sections, each having a pair of uprights connected by a rung, with the uprights of each section being slidably engaged with the corresponding uprights of an adjacent section, the rung of each section being spaced from the end from which the adjacent section slides and the uprights of each section being formed with slots to receive the rung of the adjacent section as the latter is collapsed.
2) An extensible ladder as claimed in claim 1, in which the uprights of each section are tubular.
3} An extensible ladder as claimed in claim 2, in which the tubular uprights of each section are rectangular in cross- section.
4) An extensible ladder as claimed in any preceding claim, in which each rung is provided with a pair of spring-loaded bolts which engage into apertures formed in the uprights of the adjacent section when the latter is extended.
5) An extensible ladder as claimed in claim 4, in which the spring-loaded bolts are non-circular in cross-section and the apertures into which they engage are correspondingly shaped.
6) An extensible ladder which comprises a plurality of sections, each having a pair of uprights connected by a rung, with the uprights of each section being slidably engaged with the corresponding uprights of an adjacent section and each rung having a pair of spring-loaded bolts which engage into apertures formed in the uprights of the adjacent section when the latter is extended.
7) An extensible ladder as claimed in claim 6, in which the rung of each section is spaced from the end from which the adjacent section slides and the uprights of each section are formed with slots to receive the rung of 'the adjacent section as the latter is collapsed.
8) An extensible ladder as claimed in claim 6 or 7 , in which the uprights of each section are tubular.
9) An extensible ladder as claimed in claim 8, in which the tubular uprights of each section are rectangular in cross- section.
10) An extensible ladder as claim in any one of claims 6 to 9, in which the spring-loaded bolts are non-circular in cross- section and the apertures into which they engage are correspondingly shaped.
PCT/GB1992/001319 1991-07-18 1992-07-17 Extensible ladder WO1993002271A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB919115527A GB9115527D0 (en) 1991-07-18 1991-07-18 Extensible ladder
GB9115527.5 1991-07-18

Publications (1)

Publication Number Publication Date
WO1993002271A1 true WO1993002271A1 (en) 1993-02-04

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ID=10698559

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1992/001319 WO1993002271A1 (en) 1991-07-18 1992-07-17 Extensible ladder

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WO (1) WO1993002271A1 (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995008689A1 (en) * 1993-09-24 1995-03-30 Luis Blanco Gris New arrangement of steps applicable to dismountable stairs
US5738186A (en) * 1994-03-01 1998-04-14 Foxdale Developments Limited Extensible ladder
US8225906B2 (en) 2008-08-22 2012-07-24 Core Distribution, Inc. Extendable/retractable ladder
US8387753B2 (en) 2006-06-30 2013-03-05 Core Distribution, Inc. Ergonomic extendable/retractable ladder
US9121177B1 (en) * 2009-01-06 2015-09-01 Felix L. Sorkin Upper beam slab bolster for use in construction
US10731413B2 (en) 2014-12-02 2020-08-04 Core Distribution, Inc. Foldable ladder
US11174678B2 (en) 2017-11-08 2021-11-16 Core Distribution, Inc. Locking assembly for a telescoping ladder
US11795760B2 (en) 2019-10-24 2023-10-24 Core Distribution, Inc. Ladder tripod assembly and system

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE73768C (en) * A. KREBS in Posen, Fischerei 31 Locking device for rescue ladders, the stiles of which are formed by telescoping tubes
US1712942A (en) * 1927-12-29 1929-05-14 Hiram K Smith Collapsible ladder
US2542398A (en) * 1945-07-28 1951-02-20 Mary Crumpton Murray Ladder
US2827216A (en) * 1955-05-25 1958-03-18 Leonard B Napolitano Telescopic step or rung ladders
US2993561A (en) * 1959-08-13 1961-07-25 Cyril J Watson Collapsible ladder
US3653463A (en) * 1970-06-22 1972-04-04 E T Hannan & Associates Inc Collapsible ladder arrangement
FR2415715A1 (en) * 1978-01-27 1979-08-24 Genries Pierre Replacement rung for hollow section ladder - consists of sleeve with fixed and recoil sprung sliding pins in opposite ends

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE73768C (en) * A. KREBS in Posen, Fischerei 31 Locking device for rescue ladders, the stiles of which are formed by telescoping tubes
US1712942A (en) * 1927-12-29 1929-05-14 Hiram K Smith Collapsible ladder
US2542398A (en) * 1945-07-28 1951-02-20 Mary Crumpton Murray Ladder
US2827216A (en) * 1955-05-25 1958-03-18 Leonard B Napolitano Telescopic step or rung ladders
US2993561A (en) * 1959-08-13 1961-07-25 Cyril J Watson Collapsible ladder
US3653463A (en) * 1970-06-22 1972-04-04 E T Hannan & Associates Inc Collapsible ladder arrangement
FR2415715A1 (en) * 1978-01-27 1979-08-24 Genries Pierre Replacement rung for hollow section ladder - consists of sleeve with fixed and recoil sprung sliding pins in opposite ends

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995008689A1 (en) * 1993-09-24 1995-03-30 Luis Blanco Gris New arrangement of steps applicable to dismountable stairs
US5738186A (en) * 1994-03-01 1998-04-14 Foxdale Developments Limited Extensible ladder
US8387753B2 (en) 2006-06-30 2013-03-05 Core Distribution, Inc. Ergonomic extendable/retractable ladder
US8225906B2 (en) 2008-08-22 2012-07-24 Core Distribution, Inc. Extendable/retractable ladder
US10053912B2 (en) 2008-08-22 2018-08-21 Core Distribution, Inc. Extendable / retractable ladder
US10753149B2 (en) 2008-08-22 2020-08-25 Core Distribution, Inc. Extendable / retractable ladder
US9121177B1 (en) * 2009-01-06 2015-09-01 Felix L. Sorkin Upper beam slab bolster for use in construction
US10731413B2 (en) 2014-12-02 2020-08-04 Core Distribution, Inc. Foldable ladder
US11174678B2 (en) 2017-11-08 2021-11-16 Core Distribution, Inc. Locking assembly for a telescoping ladder
US11795760B2 (en) 2019-10-24 2023-10-24 Core Distribution, Inc. Ladder tripod assembly and system

Also Published As

Publication number Publication date
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